freebsd-skq/sys/netipsec/xform_esp.c
ae 070fa67a64 Change ipsec_address() and ipsec_logsastr() functions to take two
additional arguments - buffer and size of this buffer.

ipsec_address() is used to convert sockaddr structure to presentation
format. The IPv6 part of this function returns pointer to the on-stack
buffer and at the moment when it will be used by caller, it becames
invalid. IPv4 version uses 4 static buffers and returns pointer to
new buffer each time when it called. But anyway it is still possible
to get corrupted data when several threads will use this function.

ipsec_logsastr() is used to format string about SA entry. It also
uses static buffer and has the same problem with concurrent threads.

To fix these problems add the buffer pointer and size of this
buffer to arguments. Now each caller will pass buffer and its size
to these functions. Also convert all places where these functions
are used (except disabled code).

And now ipsec_address() uses inet_ntop() function from libkern.

PR:		185996
Differential Revision:	https://reviews.freebsd.org/D2321
Reviewed by:	gnn
Sponsored by:	Yandex LLC
2015-04-18 16:58:33 +00:00

994 lines
25 KiB
C

/* $FreeBSD$ */
/* $OpenBSD: ip_esp.c,v 1.69 2001/06/26 06:18:59 angelos Exp $ */
/*-
* The authors of this code are John Ioannidis (ji@tla.org),
* Angelos D. Keromytis (kermit@csd.uch.gr) and
* Niels Provos (provos@physnet.uni-hamburg.de).
*
* The original version of this code was written by John Ioannidis
* for BSD/OS in Athens, Greece, in November 1995.
*
* Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
* by Angelos D. Keromytis.
*
* Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
* and Niels Provos.
*
* Additional features in 1999 by Angelos D. Keromytis.
*
* Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
* Angelos D. Keromytis and Niels Provos.
* Copyright (c) 2001 Angelos D. Keromytis.
*
* Permission to use, copy, and modify this software with or without fee
* is hereby granted, provided that this entire notice is included in
* all copies of any software which is or includes a copy or
* modification of this software.
* You may use this code under the GNU public license if you so wish. Please
* contribute changes back to the authors under this freer than GPL license
* so that we may further the use of strong encryption without limitations to
* all.
*
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
* MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
* PURPOSE.
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/random.h>
#include <sys/rwlock.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_ecn.h>
#include <netinet/ip6.h>
#include <netipsec/ipsec.h>
#include <netipsec/ah.h>
#include <netipsec/ah_var.h>
#include <netipsec/esp.h>
#include <netipsec/esp_var.h>
#include <netipsec/xform.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#include <netipsec/ipsec6.h>
#include <netinet6/ip6_ecn.h>
#endif
#include <netipsec/key.h>
#include <netipsec/key_debug.h>
#include <opencrypto/cryptodev.h>
#include <opencrypto/xform.h>
VNET_DEFINE(int, esp_enable) = 1;
VNET_PCPUSTAT_DEFINE(struct espstat, espstat);
VNET_PCPUSTAT_SYSINIT(espstat);
#ifdef VIMAGE
VNET_PCPUSTAT_SYSUNINIT(espstat);
#endif /* VIMAGE */
SYSCTL_DECL(_net_inet_esp);
SYSCTL_INT(_net_inet_esp, OID_AUTO, esp_enable,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(esp_enable), 0, "");
SYSCTL_VNET_PCPUSTAT(_net_inet_esp, IPSECCTL_STATS, stats,
struct espstat, espstat,
"ESP statistics (struct espstat, netipsec/esp_var.h");
static int esp_input_cb(struct cryptop *op);
static int esp_output_cb(struct cryptop *crp);
/*
* NB: this is public for use by the PF_KEY support.
* NB: if you add support here; be sure to add code to esp_attach below!
*/
struct enc_xform *
esp_algorithm_lookup(int alg)
{
if (alg >= ESP_ALG_MAX)
return NULL;
switch (alg) {
case SADB_EALG_DESCBC:
return &enc_xform_des;
case SADB_EALG_3DESCBC:
return &enc_xform_3des;
case SADB_X_EALG_AES:
return &enc_xform_rijndael128;
case SADB_X_EALG_BLOWFISHCBC:
return &enc_xform_blf;
case SADB_X_EALG_CAST128CBC:
return &enc_xform_cast5;
case SADB_X_EALG_SKIPJACK:
return &enc_xform_skipjack;
case SADB_EALG_NULL:
return &enc_xform_null;
case SADB_X_EALG_CAMELLIACBC:
return &enc_xform_camellia;
}
return NULL;
}
size_t
esp_hdrsiz(struct secasvar *sav)
{
size_t size;
if (sav != NULL) {
/*XXX not right for null algorithm--does it matter??*/
IPSEC_ASSERT(sav->tdb_encalgxform != NULL,
("SA with null xform"));
if (sav->flags & SADB_X_EXT_OLD)
size = sizeof (struct esp);
else
size = sizeof (struct newesp);
size += sav->tdb_encalgxform->blocksize + 9;
/*XXX need alg check???*/
if (sav->tdb_authalgxform != NULL && sav->replay)
size += ah_hdrsiz(sav);
} else {
/*
* base header size
* + max iv length for CBC mode
* + max pad length
* + sizeof (pad length field)
* + sizeof (next header field)
* + max icv supported.
*/
size = sizeof (struct newesp) + EALG_MAX_BLOCK_LEN + 9 + 16;
}
return size;
}
/*
* esp_init() is called when an SPI is being set up.
*/
static int
esp_init(struct secasvar *sav, struct xformsw *xsp)
{
struct enc_xform *txform;
struct cryptoini cria, crie;
int keylen;
int error;
txform = esp_algorithm_lookup(sav->alg_enc);
if (txform == NULL) {
DPRINTF(("%s: unsupported encryption algorithm %d\n",
__func__, sav->alg_enc));
return EINVAL;
}
if (sav->key_enc == NULL) {
DPRINTF(("%s: no encoding key for %s algorithm\n",
__func__, txform->name));
return EINVAL;
}
if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) {
DPRINTF(("%s: 4-byte IV not supported with protocol\n",
__func__));
return EINVAL;
}
keylen = _KEYLEN(sav->key_enc);
if (txform->minkey > keylen || keylen > txform->maxkey) {
DPRINTF(("%s: invalid key length %u, must be in the range "
"[%u..%u] for algorithm %s\n", __func__,
keylen, txform->minkey, txform->maxkey,
txform->name));
return EINVAL;
}
/*
* NB: The null xform needs a non-zero blocksize to keep the
* crypto code happy but if we use it to set ivlen then
* the ESP header will be processed incorrectly. The
* compromise is to force it to zero here.
*/
sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize);
sav->iv = (caddr_t) malloc(sav->ivlen, M_XDATA, M_WAITOK);
key_randomfill(sav->iv, sav->ivlen); /*XXX*/
/*
* Setup AH-related state.
*/
if (sav->alg_auth != 0) {
error = ah_init0(sav, xsp, &cria);
if (error)
return error;
}
/* NB: override anything set in ah_init0 */
sav->tdb_xform = xsp;
sav->tdb_encalgxform = txform;
/* Initialize crypto session. */
bzero(&crie, sizeof (crie));
crie.cri_alg = sav->tdb_encalgxform->type;
crie.cri_klen = _KEYBITS(sav->key_enc);
crie.cri_key = sav->key_enc->key_data;
/* XXX Rounds ? */
if (sav->tdb_authalgxform && sav->tdb_encalgxform) {
/* init both auth & enc */
crie.cri_next = &cria;
error = crypto_newsession(&sav->tdb_cryptoid,
&crie, V_crypto_support);
} else if (sav->tdb_encalgxform) {
error = crypto_newsession(&sav->tdb_cryptoid,
&crie, V_crypto_support);
} else if (sav->tdb_authalgxform) {
error = crypto_newsession(&sav->tdb_cryptoid,
&cria, V_crypto_support);
} else {
/* XXX cannot happen? */
DPRINTF(("%s: no encoding OR authentication xform!\n",
__func__));
error = EINVAL;
}
return error;
}
/*
* Paranoia.
*/
static int
esp_zeroize(struct secasvar *sav)
{
/* NB: ah_zerorize free's the crypto session state */
int error = ah_zeroize(sav);
if (sav->key_enc)
bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc));
if (sav->iv) {
free(sav->iv, M_XDATA);
sav->iv = NULL;
}
sav->tdb_encalgxform = NULL;
sav->tdb_xform = NULL;
return error;
}
/*
* ESP input processing, called (eventually) through the protocol switch.
*/
static int
esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
{
char buf[128];
struct auth_hash *esph;
struct enc_xform *espx;
struct tdb_crypto *tc;
int plen, alen, hlen;
struct newesp *esp;
struct cryptodesc *crde;
struct cryptop *crp;
IPSEC_ASSERT(sav != NULL, ("null SA"));
IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform"));
alen = 0;
/* Valid IP Packet length ? */
if ( (skip&3) || (m->m_pkthdr.len&3) ){
DPRINTF(("%s: misaligned packet, skip %u pkt len %u",
__func__, skip, m->m_pkthdr.len));
ESPSTAT_INC(esps_badilen);
m_freem(m);
return EINVAL;
}
/* XXX don't pullup, just copy header */
IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp));
esph = sav->tdb_authalgxform;
espx = sav->tdb_encalgxform;
/* Determine the ESP header length */
if (sav->flags & SADB_X_EXT_OLD)
hlen = sizeof (struct esp) + sav->ivlen;
else
hlen = sizeof (struct newesp) + sav->ivlen;
/* Authenticator hash size */
if (esph != NULL) {
switch (esph->type) {
case CRYPTO_SHA2_256_HMAC:
case CRYPTO_SHA2_384_HMAC:
case CRYPTO_SHA2_512_HMAC:
alen = esph->hashsize/2;
break;
default:
alen = AH_HMAC_HASHLEN;
break;
}
}
/*
* Verify payload length is multiple of encryption algorithm
* block size.
*
* NB: This works for the null algorithm because the blocksize
* is 4 and all packets must be 4-byte aligned regardless
* of the algorithm.
*/
plen = m->m_pkthdr.len - (skip + hlen + alen);
if ((plen & (espx->blocksize - 1)) || (plen <= 0)) {
DPRINTF(("%s: payload of %d octets not a multiple of %d octets,"
" SA %s/%08lx\n", __func__,
plen, espx->blocksize, ipsec_address(&sav->sah->saidx.dst,
buf, sizeof(buf)), (u_long) ntohl(sav->spi)));
ESPSTAT_INC(esps_badilen);
m_freem(m);
return EINVAL;
}
/*
* Check sequence number.
*/
if (esph != NULL && sav->replay != NULL &&
!ipsec_chkreplay(ntohl(esp->esp_seq), sav)) {
DPRINTF(("%s: packet replay check for %s\n", __func__,
ipsec_logsastr(sav, buf, sizeof(buf)))); /*XXX*/
ESPSTAT_INC(esps_replay);
m_freem(m);
return ENOBUFS; /*XXX*/
}
/* Update the counters */
ESPSTAT_ADD(esps_ibytes, m->m_pkthdr.len - (skip + hlen + alen));
/* Get crypto descriptors */
crp = crypto_getreq(esph && espx ? 2 : 1);
if (crp == NULL) {
DPRINTF(("%s: failed to acquire crypto descriptors\n",
__func__));
ESPSTAT_INC(esps_crypto);
m_freem(m);
return ENOBUFS;
}
/* Get IPsec-specific opaque pointer */
tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen,
M_XDATA, M_NOWAIT | M_ZERO);
if (tc == NULL) {
crypto_freereq(crp);
DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
ESPSTAT_INC(esps_crypto);
m_freem(m);
return ENOBUFS;
}
if (esph != NULL) {
struct cryptodesc *crda = crp->crp_desc;
IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor"));
/* Authentication descriptor */
crda->crd_skip = skip;
crda->crd_len = m->m_pkthdr.len - (skip + alen);
crda->crd_inject = m->m_pkthdr.len - alen;
crda->crd_alg = esph->type;
crda->crd_key = sav->key_auth->key_data;
crda->crd_klen = _KEYBITS(sav->key_auth);
/* Copy the authenticator */
m_copydata(m, m->m_pkthdr.len - alen, alen,
(caddr_t) (tc + 1));
/* Chain authentication request */
crde = crda->crd_next;
} else {
crde = crp->crp_desc;
}
/* Crypto operation descriptor */
crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
crp->crp_buf = (caddr_t) m;
crp->crp_callback = esp_input_cb;
crp->crp_sid = sav->tdb_cryptoid;
crp->crp_opaque = (caddr_t) tc;
/* These are passed as-is to the callback */
tc->tc_spi = sav->spi;
tc->tc_dst = sav->sah->saidx.dst;
tc->tc_proto = sav->sah->saidx.proto;
tc->tc_protoff = protoff;
tc->tc_skip = skip;
KEY_ADDREFSA(sav);
tc->tc_sav = sav;
/* Decryption descriptor */
IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor"));
crde->crd_skip = skip + hlen;
crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
crde->crd_inject = skip + hlen - sav->ivlen;
crde->crd_alg = espx->type;
crde->crd_key = sav->key_enc->key_data;
crde->crd_klen = _KEYBITS(sav->key_enc);
/* XXX Rounds ? */
return (crypto_dispatch(crp));
}
/*
* ESP input callback from the crypto driver.
*/
static int
esp_input_cb(struct cryptop *crp)
{
char buf[128];
u_int8_t lastthree[3], aalg[AH_HMAC_MAXHASHLEN];
int hlen, skip, protoff, error, alen;
struct mbuf *m;
struct cryptodesc *crd;
struct auth_hash *esph;
struct enc_xform *espx;
struct tdb_crypto *tc;
struct secasvar *sav;
struct secasindex *saidx;
caddr_t ptr;
crd = crp->crp_desc;
IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!"));
tc = (struct tdb_crypto *) crp->crp_opaque;
IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
skip = tc->tc_skip;
protoff = tc->tc_protoff;
m = (struct mbuf *) crp->crp_buf;
sav = tc->tc_sav;
IPSEC_ASSERT(sav != NULL, ("null SA!"));
saidx = &sav->sah->saidx;
IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
saidx->dst.sa.sa_family == AF_INET6,
("unexpected protocol family %u", saidx->dst.sa.sa_family));
esph = sav->tdb_authalgxform;
espx = sav->tdb_encalgxform;
/* Check for crypto errors */
if (crp->crp_etype) {
/* Reset the session ID */
if (sav->tdb_cryptoid != 0)
sav->tdb_cryptoid = crp->crp_sid;
if (crp->crp_etype == EAGAIN)
return (crypto_dispatch(crp));
ESPSTAT_INC(esps_noxform);
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
ESPSTAT_INC(esps_crypto);
DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
error = EINVAL;
goto bad;
}
ESPSTAT_INC(esps_hist[sav->alg_enc]);
/* If authentication was performed, check now. */
if (esph != NULL) {
switch (esph->type) {
case CRYPTO_SHA2_256_HMAC:
case CRYPTO_SHA2_384_HMAC:
case CRYPTO_SHA2_512_HMAC:
alen = esph->hashsize/2;
break;
default:
alen = AH_HMAC_HASHLEN;
break;
}
AHSTAT_INC(ahs_hist[sav->alg_auth]);
/* Copy the authenticator from the packet */
m_copydata(m, m->m_pkthdr.len - alen, alen, aalg);
ptr = (caddr_t) (tc + 1);
/* Verify authenticator */
if (bcmp(ptr, aalg, alen) != 0) {
DPRINTF(("%s: authentication hash mismatch for "
"packet in SA %s/%08lx\n", __func__,
ipsec_address(&saidx->dst, buf, sizeof(buf)),
(u_long) ntohl(sav->spi)));
ESPSTAT_INC(esps_badauth);
error = EACCES;
goto bad;
}
/* Remove trailing authenticator */
m_adj(m, -alen);
}
/* Release the crypto descriptors */
free(tc, M_XDATA), tc = NULL;
crypto_freereq(crp), crp = NULL;
/*
* Packet is now decrypted.
*/
m->m_flags |= M_DECRYPTED;
/*
* Update replay sequence number, if appropriate.
*/
if (sav->replay) {
u_int32_t seq;
m_copydata(m, skip + offsetof(struct newesp, esp_seq),
sizeof (seq), (caddr_t) &seq);
if (ipsec_updatereplay(ntohl(seq), sav)) {
DPRINTF(("%s: packet replay check for %s\n", __func__,
ipsec_logsastr(sav, buf, sizeof(buf))));
ESPSTAT_INC(esps_replay);
error = ENOBUFS;
goto bad;
}
}
/* Determine the ESP header length */
if (sav->flags & SADB_X_EXT_OLD)
hlen = sizeof (struct esp) + sav->ivlen;
else
hlen = sizeof (struct newesp) + sav->ivlen;
/* Remove the ESP header and IV from the mbuf. */
error = m_striphdr(m, skip, hlen);
if (error) {
ESPSTAT_INC(esps_hdrops);
DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__,
ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
(u_long) ntohl(sav->spi)));
goto bad;
}
/* Save the last three bytes of decrypted data */
m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
/* Verify pad length */
if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
ESPSTAT_INC(esps_badilen);
DPRINTF(("%s: invalid padding length %d for %u byte packet "
"in SA %s/%08lx\n", __func__, lastthree[1],
m->m_pkthdr.len - skip,
ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
(u_long) ntohl(sav->spi)));
error = EINVAL;
goto bad;
}
/* Verify correct decryption by checking the last padding bytes */
if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
ESPSTAT_INC(esps_badenc);
DPRINTF(("%s: decryption failed for packet in "
"SA %s/%08lx\n", __func__, ipsec_address(
&sav->sah->saidx.dst, buf, sizeof(buf)),
(u_long) ntohl(sav->spi)));
error = EINVAL;
goto bad;
}
}
/* Trim the mbuf chain to remove trailing authenticator and padding */
m_adj(m, -(lastthree[1] + 2));
/* Restore the Next Protocol field */
m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
switch (saidx->dst.sa.sa_family) {
#ifdef INET6
case AF_INET6:
error = ipsec6_common_input_cb(m, sav, skip, protoff);
break;
#endif
#ifdef INET
case AF_INET:
error = ipsec4_common_input_cb(m, sav, skip, protoff);
break;
#endif
default:
panic("%s: Unexpected address family: %d saidx=%p", __func__,
saidx->dst.sa.sa_family, saidx);
}
KEY_FREESAV(&sav);
return error;
bad:
if (sav)
KEY_FREESAV(&sav);
if (m != NULL)
m_freem(m);
if (tc != NULL)
free(tc, M_XDATA);
if (crp != NULL)
crypto_freereq(crp);
return error;
}
/*
* ESP output routine, called by ipsec[46]_process_packet().
*/
static int
esp_output(struct mbuf *m, struct ipsecrequest *isr, struct mbuf **mp,
int skip, int protoff)
{
char buf[INET6_ADDRSTRLEN];
struct enc_xform *espx;
struct auth_hash *esph;
int hlen, rlen, padding, blks, alen, i, roff;
struct mbuf *mo = (struct mbuf *) NULL;
struct tdb_crypto *tc;
struct secasvar *sav;
struct secasindex *saidx;
unsigned char *pad;
u_int8_t prot;
int error, maxpacketsize;
struct cryptodesc *crde = NULL, *crda = NULL;
struct cryptop *crp;
sav = isr->sav;
IPSEC_ASSERT(sav != NULL, ("null SA"));
esph = sav->tdb_authalgxform;
espx = sav->tdb_encalgxform;
IPSEC_ASSERT(espx != NULL, ("null encoding xform"));
if (sav->flags & SADB_X_EXT_OLD)
hlen = sizeof (struct esp) + sav->ivlen;
else
hlen = sizeof (struct newesp) + sav->ivlen;
rlen = m->m_pkthdr.len - skip; /* Raw payload length. */
/*
* NB: The null encoding transform has a blocksize of 4
* so that headers are properly aligned.
*/
blks = espx->blocksize; /* IV blocksize */
/* XXX clamp padding length a la KAME??? */
padding = ((blks - ((rlen + 2) % blks)) % blks) + 2;
if (esph)
switch (esph->type) {
case CRYPTO_SHA2_256_HMAC:
case CRYPTO_SHA2_384_HMAC:
case CRYPTO_SHA2_512_HMAC:
alen = esph->hashsize/2;
break;
default:
alen = AH_HMAC_HASHLEN;
break;
}
else
alen = 0;
ESPSTAT_INC(esps_output);
saidx = &sav->sah->saidx;
/* Check for maximum packet size violations. */
switch (saidx->dst.sa.sa_family) {
#ifdef INET
case AF_INET:
maxpacketsize = IP_MAXPACKET;
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
maxpacketsize = IPV6_MAXPACKET;
break;
#endif /* INET6 */
default:
DPRINTF(("%s: unknown/unsupported protocol "
"family %d, SA %s/%08lx\n", __func__,
saidx->dst.sa.sa_family, ipsec_address(&saidx->dst,
buf, sizeof(buf)), (u_long) ntohl(sav->spi)));
ESPSTAT_INC(esps_nopf);
error = EPFNOSUPPORT;
goto bad;
}
if (skip + hlen + rlen + padding + alen > maxpacketsize) {
DPRINTF(("%s: packet in SA %s/%08lx got too big "
"(len %u, max len %u)\n", __func__,
ipsec_address(&saidx->dst, buf, sizeof(buf)),
(u_long) ntohl(sav->spi),
skip + hlen + rlen + padding + alen, maxpacketsize));
ESPSTAT_INC(esps_toobig);
error = EMSGSIZE;
goto bad;
}
/* Update the counters. */
ESPSTAT_ADD(esps_obytes, m->m_pkthdr.len - skip);
m = m_unshare(m, M_NOWAIT);
if (m == NULL) {
DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
ipsec_address(&saidx->dst, buf, sizeof(buf)),
(u_long) ntohl(sav->spi)));
ESPSTAT_INC(esps_hdrops);
error = ENOBUFS;
goto bad;
}
/* Inject ESP header. */
mo = m_makespace(m, skip, hlen, &roff);
if (mo == NULL) {
DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n",
__func__, hlen, ipsec_address(&saidx->dst, buf,
sizeof(buf)), (u_long) ntohl(sav->spi)));
ESPSTAT_INC(esps_hdrops); /* XXX diffs from openbsd */
error = ENOBUFS;
goto bad;
}
/* Initialize ESP header. */
bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t));
if (sav->replay) {
u_int32_t replay;
#ifdef REGRESSION
/* Emulate replay attack when ipsec_replay is TRUE. */
if (!V_ipsec_replay)
#endif
sav->replay->count++;
replay = htonl(sav->replay->count);
bcopy((caddr_t) &replay,
mtod(mo, caddr_t) + roff + sizeof(u_int32_t),
sizeof(u_int32_t));
}
/*
* Add padding -- better to do it ourselves than use the crypto engine,
* although if/when we support compression, we'd have to do that.
*/
pad = (u_char *) m_pad(m, padding + alen);
if (pad == NULL) {
DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__,
ipsec_address(&saidx->dst, buf, sizeof(buf)),
(u_long) ntohl(sav->spi)));
m = NULL; /* NB: free'd by m_pad */
error = ENOBUFS;
goto bad;
}
/*
* Add padding: random, zero, or self-describing.
* XXX catch unexpected setting
*/
switch (sav->flags & SADB_X_EXT_PMASK) {
case SADB_X_EXT_PRAND:
(void) read_random(pad, padding - 2);
break;
case SADB_X_EXT_PZERO:
bzero(pad, padding - 2);
break;
case SADB_X_EXT_PSEQ:
for (i = 0; i < padding - 2; i++)
pad[i] = i+1;
break;
}
/* Fix padding length and Next Protocol in padding itself. */
pad[padding - 2] = padding - 2;
m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1);
/* Fix Next Protocol in IPv4/IPv6 header. */
prot = IPPROTO_ESP;
m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
/* Get crypto descriptors. */
crp = crypto_getreq(esph && espx ? 2 : 1);
if (crp == NULL) {
DPRINTF(("%s: failed to acquire crypto descriptors\n",
__func__));
ESPSTAT_INC(esps_crypto);
error = ENOBUFS;
goto bad;
}
if (espx) {
crde = crp->crp_desc;
crda = crde->crd_next;
/* Encryption descriptor. */
crde->crd_skip = skip + hlen;
crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
crde->crd_flags = CRD_F_ENCRYPT;
crde->crd_inject = skip + hlen - sav->ivlen;
/* Encryption operation. */
crde->crd_alg = espx->type;
crde->crd_key = sav->key_enc->key_data;
crde->crd_klen = _KEYBITS(sav->key_enc);
/* XXX Rounds ? */
} else
crda = crp->crp_desc;
/* IPsec-specific opaque crypto info. */
tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
M_XDATA, M_NOWAIT|M_ZERO);
if (tc == NULL) {
crypto_freereq(crp);
DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
ESPSTAT_INC(esps_crypto);
error = ENOBUFS;
goto bad;
}
/* Callback parameters */
tc->tc_isr = isr;
KEY_ADDREFSA(sav);
tc->tc_sav = sav;
tc->tc_spi = sav->spi;
tc->tc_dst = saidx->dst;
tc->tc_proto = saidx->proto;
/* Crypto operation descriptor. */
crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
crp->crp_buf = (caddr_t) m;
crp->crp_callback = esp_output_cb;
crp->crp_opaque = (caddr_t) tc;
crp->crp_sid = sav->tdb_cryptoid;
if (esph) {
/* Authentication descriptor. */
crda->crd_skip = skip;
crda->crd_len = m->m_pkthdr.len - (skip + alen);
crda->crd_inject = m->m_pkthdr.len - alen;
/* Authentication operation. */
crda->crd_alg = esph->type;
crda->crd_key = sav->key_auth->key_data;
crda->crd_klen = _KEYBITS(sav->key_auth);
}
return crypto_dispatch(crp);
bad:
if (m)
m_freem(m);
return (error);
}
/*
* ESP output callback from the crypto driver.
*/
static int
esp_output_cb(struct cryptop *crp)
{
char buf[INET6_ADDRSTRLEN];
struct tdb_crypto *tc;
struct ipsecrequest *isr;
struct secasvar *sav;
struct mbuf *m;
int error;
tc = (struct tdb_crypto *) crp->crp_opaque;
IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
m = (struct mbuf *) crp->crp_buf;
isr = tc->tc_isr;
IPSECREQUEST_LOCK(isr);
sav = tc->tc_sav;
/* With the isr lock released SA pointer can be updated. */
if (sav != isr->sav) {
ESPSTAT_INC(esps_notdb);
DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
__func__, ipsec_address(&tc->tc_dst, buf, sizeof(buf)),
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
error = ENOBUFS; /*XXX*/
goto bad;
}
/* Check for crypto errors. */
if (crp->crp_etype) {
/* Reset session ID. */
if (sav->tdb_cryptoid != 0)
sav->tdb_cryptoid = crp->crp_sid;
if (crp->crp_etype == EAGAIN) {
IPSECREQUEST_UNLOCK(isr);
return (crypto_dispatch(crp));
}
ESPSTAT_INC(esps_noxform);
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
ESPSTAT_INC(esps_crypto);
DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
error = EINVAL;
goto bad;
}
ESPSTAT_INC(esps_hist[sav->alg_enc]);
if (sav->tdb_authalgxform != NULL)
AHSTAT_INC(ahs_hist[sav->alg_auth]);
/* Release crypto descriptors. */
free(tc, M_XDATA);
crypto_freereq(crp);
#ifdef REGRESSION
/* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
if (V_ipsec_integrity) {
static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN];
struct auth_hash *esph;
/*
* Corrupt HMAC if we want to test integrity verification of
* the other side.
*/
esph = sav->tdb_authalgxform;
if (esph != NULL) {
int alen;
switch (esph->type) {
case CRYPTO_SHA2_256_HMAC:
case CRYPTO_SHA2_384_HMAC:
case CRYPTO_SHA2_512_HMAC:
alen = esph->hashsize/2;
break;
default:
alen = AH_HMAC_HASHLEN;
break;
}
m_copyback(m, m->m_pkthdr.len - alen,
alen, ipseczeroes);
}
}
#endif
/* NB: m is reclaimed by ipsec_process_done. */
error = ipsec_process_done(m, isr);
KEY_FREESAV(&sav);
IPSECREQUEST_UNLOCK(isr);
return error;
bad:
if (sav)
KEY_FREESAV(&sav);
IPSECREQUEST_UNLOCK(isr);
if (m)
m_freem(m);
free(tc, M_XDATA);
crypto_freereq(crp);
return error;
}
static struct xformsw esp_xformsw = {
XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP",
esp_init, esp_zeroize, esp_input,
esp_output
};
static void
esp_attach(void)
{
xform_register(&esp_xformsw);
}
SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);